
##############################################################################

 Figure 1. Number of Articles Published in Selected PS Journals Using SEM

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Year <- c(1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 
          2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 
          2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020)

Article <- c(5, 7, 12, 15, 12, 10, 17, 11, 15, 18, 10, 15, 15, 18, 17, 
             15, 19, 12, 16, 15, 20, 18, 21, 15, 19, 26, 16, 16, 18, 19, 16)

plot(Year, Article, type = "o", col = "black", pch = 16,
     xlab = "Year", ylab = "Number of Articles", 
     main = "", 
     xaxt = "n", 
     cex.axis = 1.5,
     cex.lab = 1.3,   
     bty = "n")       

axis(1, at = seq(1990, 2020, by = 3), cex.axis = 1.5) 



#######.  End of R code 
